As the Earth burns, people are starting to consider "geoengineering":
Rivers fed by melting snow and glaciers supply water to over one-sixth of the world's population — well over a billion people. But these sources of water are quickly disappearing: the Himalayan glaciers that feed rivers in India, China, and other Asian countries could be gone in 25 years. Such effects of climate change no longer surprise scientists. But the speed at which they're happening does. "The earth appears to be changing faster than the climate models predicted," says Daniel Schrag, a professor of earth and planetary sciences at Harvard University, who advises President Obama on climate issues.One of the most popular schemes — if "popular" is the right word — is to inject large amounts of sulfates into the upper atmosphere. When Mount Pinatubo blew its top in 1991, it shot 15 million tons of sulfur dioxide into the stratosphere, and temperatures dipped an average of 0.5 °C worldwide for the next 15 months. But rainfall dropped too! According to Kevin Trenberth of the National Center for Atmospheric Research, it was 50 percent lower than the previous low of any year recorded so far! Not good.
Atmospheric levels of carbon dioxide have already climbed to 385 parts per million, well over the 350 parts per million that many scientists say is the upper limit for a relatively stable climate. And despite government-led efforts to limit carbon emissions in many countries, annual emissions from fossil-fuel combustion are going up, not down: over the last two decades, they have increased 41 percent. In the last 10 years, the concentration of carbon dioxide in the atmosphere has increased by nearly two parts per million every year. At this rate, they'll be twice preindustrial levels by the end of the century. Meanwhile, researchers are growing convinced that the climate might be more sensitive to greenhouse gases at this level than once thought. "The likelihood that we're going to avoid serious damage seems quite low," says Schrag. "The best we're going to do is probably not going to be good enough."
This shocking realization has caused many influential scientists, including Obama advisors like Schrag, to fundamentally change their thinking about how to respond to climate change. They have begun calling for the government to start funding research into geoengineering — large-scale schemes for rapidly cooling the earth.
There are other dangers: if we let the Earth become dependent on an artificial cooling system, a war or economic crisis that puts a temporary halt to the scheme could cause sudden warming of an extreme sort. In other words: once we get on the merry-go-round, it's hard to jump off. And what helps one region might hurt another, so unilaterally starting such a scheme could even start a war. But some country might still try it:
David Victor, the director of the Laboratory on International Law and Regulation at the University of California, San Diego, sees two scenarios in which it might happen. First, "the desperate Hail Mary pass": "A country quite vulnerable to changing climate is desperate to alter outcomes and sees that efforts to cut emissions are not bearing fruit. Crude geoengineering schemes could be very inexpensive, and thus this option might even be available to a Trinidad or Bangladesh — the former rich in gas exports and quite vulnerable, and the latter poor but large enough that it might do something seen as essential for survival." And second, "the Soviet-style arrogant engineering scenario": "A country run by engineers and not overly exposed to public opinion or to dissenting voices undertakes geoengineering as a national mission — much like massive building of poorly designed nuclear reactors, river diversion projects, resettlement of populations, and other national missions that are hard to pursue when the public is informed, responsive, and in power." In either case, a single country acting alone could influence the climate of the entire world.Geoengineering clearly calls for caution. But it may be the road we head down — since if human-induced climate change is a real problem, by the time its effects are clearly visible to everyone, it'll be hard to stop.
"It's not a techno-fix. It's not a Band-Aid," says
Daniel Schrag. "It's a tourniquet. There are potential side effects,
yes. But it may be better than the alternative, which is bleeding to
January 9, 2010
My friend Bruce Smith pointed out this op-ed column:
In the last year alone, so many new solar panel makers emerged in China that the price of solar power has fallen from roughly 59 cents a kilowatt hour to 16 cents, according to The Times' bureau chief here, Keith Bradsher. Meanwhile, China last week tested the fastest bullet train in the world — 217 miles per hour — from Wuhan to Guangzhou. As Bradsher noted, China "has nearly finished the construction of a high-speed rail route from Beijing to Shanghai at a cost of $23.5 billion. Trains will cover the 700-mile route in just five hours, compared with 12 hours today. By comparison, Amtrak trains require at least 18 hours to travel a similar distance from New York to Chicago".Doubtless he's trying to scare Americans into action. But from a worldwide perspective it's a great thing that China is taking the energy problem seriously... since this country will dominate the 21st century.
China is also engaged in the world's most rapid expansion of nuclear power. It is expected to build some 50 new nuclear reactors by 2020; the rest of the world combined might build 15.
"By the end of this decade, China will be dominating global production of the whole range of power equipment," said Andrew Brandler, the C.E.O. of the CLP Group, Hong Kong's largest power utility.
I want to get more seriously involved in environmental issues. The mathematics of n-categories is great fun, but it's getting harder and harder for me to convince myself that I should be working on it. Some very talented people have taken up the subject; it doesn't need me anymore. The Earth, on the other hand, is in desperate need of all our help. I don't want to look back and feel I was fiddling while Rome burned.
I'm not quite sure what to do yet — that's the main thing that's been holding me back. But I think being in Singapore will give me a new perspective, and a kind of nudge. And I'm hoping that this conference will give me some ideas:
January 10, 2010
People are working on interspecies cloning as a possible way
to resurrect extinct species like woolly mammoths... or
Arabian sand cats.
Arabian sand cats? Yes, they're not extinct yet — but they're endangered, so this is the best time to practice cloning them. Betsy Dresser is at work on this — she's the director of the Audubon Center for Research of Endangered Species. Dr. Dresser is responsible for creating a "frozen zoo" holding the frozen embryos of 75 animal species. And, she's already succeeded in implanting ordinary cats with the genome of African wild cats! The kittens grew up just fine:
This was not unexpected: Lisa had already gotten her leave approved, and the administration said mine would be too. But it's nice to be certain. Starting in July, she'll be teaching at the Department of Philosophy at NUS — the National University of Singapore. I'll be doing research at the CQT — the Centre for Quantum Technologies.
Upon getting the good news, the first thing I did is announce my new plans on the n-Category Café. Namely: I want to shift the focus of my research away from fancy abstract n-categorical math to slightly more practical things. My job at the CQT will give me a chance to explore computer science, microtraps, and quantum optics. I'll also get to interact with the Nanoscience and Nanotechnology Initiative.
But what I really want to do is help save our beleagured planet. There are so many things we need to do, that I'm sure I can find ways to help out. I'm good at math, physics, learning things, explaining them, and getting crowds of people interested in them. Surely there are ways to harness these talents in support of the Earth.
My remarks on the n-Category Café started an interesting conversation. Lots of leads to follow up!
I'm excited about this new phase of my career. Over the last decade, my work on n-categories had become a kind of race as more and more smart people got involved. What started out as free-form exploration had become more of a competitive game, at least in my own mind. And the work was becoming more and more technical. All this made me feel old and tired.
But there's a lot of mathematics and physics that I want to explore that's
less esoteric and more vitally connected to engineering, biology and
the environmental problems we face. The more I think about it, the
more ideas I get... and the younger I feel!
January 18, 2010
Some big rainstorms are headed our way...
And while Southern California desperately needs rain, the charred
mountain slopes will turn into mud when the big storms hit. So,
we'll see mudslides. All part of the process of deforestation
and soil loss caused by global warming in this part of the world.
January 19, 2010
Lots of rain!
January 20, 2010
Much more rain — we've had about 2.3 inches in the last
48 hours! Jim Dolan and I talked about math at a restaurant
today. Walking there it seemed very windy and rainy, but after
we got there it really started pouring — with lightning and
sleet! Sleet is pretty rare here.
Later, I found out there was a tornado in Los Angeles today, four waterspouts, and some mudslides too. More big storms are expected tomorrow and the next day as well.
I told you about my brand-new compost pile on October 22nd. It's great! I turned it over last week, and now I've got a Biostack Bin half full of brand new dark rich soil! We'll use it to improve the dirt on the east side of the house, where we grow tomatos.
You wouldn't believe how much happier you'll feel when you can take all your yard waste, grapefruit peels, banana peels, coffee grounds, tea leaves and other vegetable matter and do something useful with it. For me, throwing out trash was always an occasion for mild guilt: I couldn't help but imagine plastic bags of my junk, mummified in the local dump for centuries to come. Now I feel downright productive — at least when I'm taking stuff out to the compost pile. And because Lisa and I don't buy tons of crud in plastic packaging, and we eat pretty well — more fruits and vegetables than meat and junk food — the amount of trash we send to the dump has been drastically reduced, so even putting trash out for the garbage trucks elicits feelings of smug self-satisfaction, rather than shame.
You met Martin Gisser in my September 1st diary entry. He read my entry about compost piles, and today he sent me an email about terra preta and biochar.
To set the stage: in the Amazon Basin, there's a lot of nice rich soil. This is man-made! The soil there is naturally infertile, but between 450 BC and 950 AD, the natives enriched it using bone, manure and charcoal... producing a layer of soil full of organic material as much as 2 meters thick. This is called "terra preta", which means "black earth" in Portuguese.
Besides improving the soil, there's another wonderful thing about turning plant matter into charcoal and burying it this way. It keeps the carbon underground for hundreds of thousands of years. Thus, it significantly slows the rate at which carbon returns to the atmosphere in the form of carbon dioxide!
In fact, the people believe the only real chance to fight global warming on the massive scale needed is via massive "biochar" projects. It's low tech: anyone can do it.
For example, in the Guardian, James Lovelock wrote:
I said in my recent book that perhaps the only tool we had to bring carbon dioxide back to pre-industrial levels was to let the biosphere pump it from the air for us. It currently removes 550bn tons a year, about 18 times more than we emit, but 99.9% of the carbon captured this way goes back to the air as CO2 when things are eaten.I need to learn more about this. But anyway, here's Martin Gisser's email:
What we have to do is turn a portion of all the waste of agriculture into charcoal and bury it. Consider grain like wheat or rice; most of the plant mass is in the stems, stalks and roots and we only eat the seeds. So instead of just ploughing in the stalks or turning them into cardboard, make it into charcoal and bury it or sink it in the ocean. We don't need plantations or crops planted for biochar, what we need is a charcoal maker on every farm so the farmer can turn his waste into carbon. Charcoal making might even work instead of landfill for waste paper and plastic.
Incidentally, in making charcoal this way, there is a by-product of biofuel that the farmer can sell. If we are to make this idea work it is vital that it pays for itself and requires no subsidy. Subsidies almost always breed scams and this is true of most forms of renewable energy now proposed and used. No one would invest in plantations to make charcoal without a subsidy, but if we can show the farmers they can turn their waste to profit they will do it freely and help us and Gaia too.
There is no chance that carbon capture and storage from industry or power stations will make a dent in CO2 accumulation, even if we had the will and money to do it. But we have to grow food, so why not help Gaia do the job of CO2 removal for us?
Here's a tip for the c21st compost fetishist: Try producing Terra Preta! It is the only tool we have at hand to repair the climate system. Paradoxically, it's simple Stone Age technology.Sadly, he refused to make a video demonstrating his technique.
In the humid and hot tropics it is trivial to produce: Add charcoal dust to soil and get amazing soil productivity boosts:
Here's how I do it:
- Pure charcoal eats up surrounding soil.
- Charcoal is water repellant at first. You need to cook it, e.g. by flushing the fireplace with water.
I'm heating my snowy Bavarian Forest home with briquettes of compressed shredded wood. When they are red glowing, I sometimes put some into a bucket with water. (Of course using an iron shovel and bucket not coated with plastic. Beware the dioxins!) Then I pee into the bucket (I no longer waste my precious pee to the toilet) to improve the carbon/nitrogen balance and then mix it into the young compost heap (I got 3 heaps of different age). The stuff tends to emit smelly ammonia (NH3) first, which luckily is water soluble and important food for soil organisms. So I cover the peed char with other wet stuff. I can't say if it makes a difference, because there's no difference to make: There was no garden soil before I came and saw...
In the afternoon, Lisa and I drove over to Irvine. Lisa went on a walk with Greg Benford while I attended a meeting of the Southern California Reading Group in the Philosophy of Physics. This is a group that meets about three times per quarter at UC Irvine to discussion the foundations of physics. We had a nice long rambling question-and-answer session where I explained the good and bad sides of string theory and loop quantum gravity, why I quit working on quantum gravity and started working on n-categories, and why I recently stopped working on n-categories and started trying to find a way to help save the planet. I finally met Craig Callender, who helped edit the book Physics Meets Philosophy at the Planck Length. I have a paper in there, but I'd never met him before! Now he's at U.C. San Diego. So is Christian Wüthrich, who invited me to this meeting. I also met David Malament and Jeffrey Barrett from the Department of Logic and Philosophy of Science at U.C. Irvine, and some other interesting people.
After the talk we had dinner at the Steelhead Brewing Company, and I spent a lot of time talking to James Owen Weatherall, who already has a PhD in physics but is now a grad student with Malament. He told me that Geroch and Jang had proved a theorem that in general relativity, a test particle must move along a geodesic — a fact sometimes treated as an axiom. A later paper by Geroch and Jürgen Ehlers, generalized this to to the case where the particle's energy-momentum is included in Einstein's equation. Weatherall has been working on similar results in the coordinate-free formulation of Newtonian gravity, sometimes called Newton-Cartan gravity. I've been sort of interested in Newton-Cartan gravity, so I was happy to hear that it's explained in some lectures notes by Malament.
Later I spoke to Craig Callender, and it turned out he had gotten serious about environmentalism too. His approach was to start teaching courses on the subject. He sounded a bit apologetic for only doing that, but as he correctly pointed out, there's a big multiplier effect when you teach 100 people something. So maybe when I return to U. C. Riverside after my Singapore jaunt I should try to do something like that... as well as the other things I'm vaguely planning. I need to see if there's some sort of interdisciplinary program I could hook onto.
We also talked about decision theory and the whole problem of how to make decisions about huge problems in the face of great uncertainty and insufficient evidence. Jeffrey Barrett mentioned the problem of "what if it's already too late to stop a disaster?", and pointed me to the following paper. But we agreed that even if it's too late to stop a disaster, it can be worthwhile trying to keep the disaster from becoming even worse! And I think this is very much true here, both when it comes to human suffering and the extinction of species.
Abstract: The severity of damaging human-induced climate change depends not only on the magnitude of the change but also on the potential for irreversibility. This paper shows that the climate change that takes place due to increases in carbon dioxide concentration is largely irreversible for 1,000 years after emissions stop. Following cessation of emissions, removal of atmospheric carbon dioxide decreases radiative forcing, but is largely compensated by slower loss of heat to the ocean, so that atmospheric temperatures do not drop significantly for at least 1,000 years. Among illustrative irreversible impacts that should be expected if atmospheric carbon dioxide concentrations increase from current levels near 385 parts per million by volume (ppmv) to a peak of 450-600 ppmv over the coming century are irreversible dry-season rainfall reductions in several regions comparable to those of the "dust bowl" era and inexorable sea level rise. Thermal expansion of the warming ocean provides a conservative lower limit to irreversible global average sea level rise of at least 0.4-1.0 meters if 21st century CO2 concentrations exceed 600 ppmv and 0.6-1.9 meters for peak CO2 concentrations exceeding ∼1,000 ppmv. Additional contributions from glaciers and ice sheet contributions to future sea level rise are uncertain but may equal or exceed several meters over the next millennium or longer.Here it's worth comparing this article which focuses on the really long term. It's not consoling, and perhaps not very important for us short-termers, but still interesting:
In about 300 years, all available fossil fuels may well have been consumed. Over the following centuries, excess carbon dioxide will naturally dissolve into the oceans or get trapped by the formation of carbonate minerals. Such processes won't be offset by the industrial emissions we see today, and atmospheric carbon dioxide will slowly decline toward preindustrial levels. In about 2,000 years, when the types of planetary motions that can induce polar cooling start to coincide again, the current warming trend will be a distant memory.I don't know if anyone is thinking about these longer-term climate issues very seriously. Maybe Cocks' book Energy Demand and Climate Change is a place to look.
This means that humanity will be hit by a one-two punch the likes of which we have never seen. Nature is as unforgiving to men as it was to dinosaurs; advanced civilization will not survive unless we develop energy sources that curb the carbon emissions heating the planet today and help us fend off the cold when the ice age comes. Solar, nuclear, and other non-fossil–fuel energy sources need to be developed now, before carbon emissions get out of hand.
After dinnner I rejoined Lisa and Greg, who'd had dinner at
a nearby Indian restaurant, and we went over to his house.
Some interesting tidbits: Russia is again starting to send
a lot of spies to the US.
Buzz Aldrin told Benford that some of us may live to see the day
when nobody still alive ever set foot on the Moon. Winston Churchill
wrote an alternative-history piece called "What if the North
had won the war?" - set in a universe where the South won the
January 24, 2010
I've been corresponding with the mathematician André Joyal about
climate change. I wrote:
I'd like to figure out some way to use my skills to help the environment, and lure other mathematicians into doing the same. I think a lot of people want to do something, but aren't quite sure what. Maybe I can find out some things for mathematicians to do.He replied:
I see it as a kind of moral obligation to stop climate warming and save the biosphere. The problem is to know how. I spent almost a year reading everything I could on the subject of climate warming and I became acutely aware of the danger. Many people agree with me, but nothing seems to be happening at the moment! The scale of the problem is so enormous that we all feel powerless.
I liked the book of Harald Welzer because it contains a clear analysis of the social-psychological-historical-cultural aspects of problem. He thinks that we cannot convince people to make important changes in their life if they cannot see the benefit of these changes in their life. He thinks that climate warming is a special case of a larger problem which people may truly want to solve because they will be able to see the benefits of solving it in their life. I interpret this as a wake-up call, a call for a cultural revolution, of metamorphosis of the culture. This seems utopian, but we don't have the choice. We will have to take our dreams seriously. Of course, we should remain very realistic, rational and scientific. Put differently, we should begin to forge strong dreams and makes serious efforts to realise them.
There is a kind of philosophical problem here, because our perception of reality is very much influenced by our culture. Culture is fundamentally a good thing, but it is inherited from the past, adapted to solving the problems of the past. It may inhibit our vision of the future. I have great admiration for the founding fathers of America because they were able to free themselves from the past, to perceive the future. Of course, the historical context made it possible. This is why we should not miss every opportunity of making changes in the right direction. An accumulation of small changes can lead to a fundamental transformation. Even a small change not directly related to the problem of climate warming is good. Maybe we could make some changes in our way of doing mathematics and publishing.
They're right! I checked, and the story is roughly this. The Roman calendar started out like this:
Martius (31 days)
Aprilis (30 days)
Maius (31 days)
Iunius (30 days)
Quintilis (31 days)
Sextilis (30 days)
September (30 days)
October (31 days)
November (30 days)
December (30 days)
61 days in winter were not assigned to any month!
In 713 BC, the king of Rome added January and February. Opinions differ on the details, but Plutarch says it went like this:
Then, later, Julius Caesar got a month named after him. And then came one for Augustus Caesar. So, by 45 BC the calendar looked like this:
Februarius (28, or in leap years: 29)
January 30, 2010
Today I went to this conference:
So, what do we do? In 1961, Shockley and Quiesser wrote a paper on the limiting efficiency of a solar cell. It's limited by thermodynamical reasons: since anything that can absorb energy can also emit it, any solar cell also acts as a light-emitting diode.
What are the tricks used to approach this theoretical efficiency? Multijunctions use layers of different materials to catch photons of different frequencies. These are expensive, so people use a lens to focus more sunlight on the photovoltaic cell. See the Umuwa Solar Power Station in Australia. But then the cells get hot and need to be cooled.
Roughening the surface of a solar cell promotes light trapping, by large factors! Light bounces around ergodically and has more chances to get absorbed and turned into useful power. There are theoretical limits on how well this trick works. But those limits were derived using ray optics, where we assume light moves in straight lines. But we can beat those limits by leaving the regime where the ray-optics approximation holds good. In other words, make the surface complicated at length scales comparable to the wavelength at light.
For example: we can grow silicon wires from vapor! See Brendan M. Kayes et al in App. Phys. Lett. They can form densely packed structures that absorb more light:
Also, with such structures the charge carriers don't need to travel so far to get from the n-type material to the p-type material, which boosts efficiency.
There are other tricks, still just under development. Using surface plasmons we can adjust the dispersion relations to create materials with really low group velocity. We can create meta-materials and meta-atoms. Using these, we can make materials with negative refractive index, like n = -5!
These exhibit a reversed version of the ordinary Goos-Hänchen effect. In the ordinary version, light "slips" a little before reflecting during total internal reflection inside a material of higher refractive index (like glass) surrounded by one of lower refractive index (like air). The "slip" is actually a slight displacement of its wave crests from their expected location — a "phase slip". But for a material of negative refractive index, the light slips backwards. This allows for resonant states where light gets trapped in thin films. Maybe this can be used to make better solar cells.
Salt gets incorporated into sea ice via millimeter-scale brine inclusions between ice platelets, forming a "dendritic platelet structure". Melting sea ice forms fresh water in melt ponds atop the ice, while brine sinks down to form "bottom water", driving the global thermohaline conveyor belt.
When it gets hotter, the Earth's poles get less white, so they absorb more light, making it hotter: this is "ice albedo feedback". Ice albedo feedback is largely controlled by melt ponds. So questions like this are very important: when do they get larger, and when do they drain out?
Sea ice is diminishing rapidly in the Arctic — much faster than the climate models predicted. There's a lot less sea ice in the Antarctic, mainly in the Wedell Sea, and there it seems to be growing. In the Arctic, winter sea ice has diminished in area by about 10% from 1978 to 2008. But summer sea ice has diminished by about 40%! It took a huge plunge in 2007, leading to a 500% increase in solar heat input in this area due to the ice albedo effect. See Perovich et al in Geophysical Research Letters.
The icea thickness distribution equation was worked out by Thorndike et al in 1975. The heat equation for ice and snow was worked out by Maykut and Understeiner in 1971. Sea ice dynamics was studied by Kibler.
Ice floes have two fractal regimes, one from 1 to 20 meters, another from 100 to 1500 meters. Brine channels also have a fractal character, well modeled by diffusion limited aggregation. Brine starts flowing when there's about 5% of brine in the ice - a kind of percolation problem familiar in statistical mechanics. Here's what it looks like when there's 5.7% brine:
Polynyas occupy .001% of the overall area in Antarctic sea ice, but create 1% of the icea. Icy cold catabatic winds blow off the mainland, pushing away ice and creating patches of open water — poylnyas — which then refreeze.
Nobody knows why polycrystalline metals have a log-normal distribution of crystal sizes. Similar behavior, also unexplained, is seen in sea ice.
There was anomalous export of sea ice through Fran Strait in the 1990s, which may have been one of the preconditions for high ice albedo feedback.
20-40% of sea ice is formed by surface flooding followed by refreezing. This was not included in the sea ice models that gave such inaccurate predictions.
The food chain is founded on diatoms. These form extracellular polymeric substances (EPS), goopy mucus-like stuff made of polysaccharides that protects them and serves as antifreeze. There's a lot of this stuff; the ice gets visibly stained by it.
For more, see:
Complete simulation of the Navier-Stokes equation is too computationally intensive, so people use "mesoscale" simulation for weather simulation, but we need more fine-grained simulations to see how much wind a turbine will get. A famous Brookhaven study suggested that the power spectrum of wind has peaks at 4 days, 1/2 day, and 1 minute. This perhaps justifies an approach where different length scales are treated separately and the results then combined somehow. Night air is stable, day air is often not, since the ground is hot and hot air rises. Eddy diffusivity is modeled by Monin-Obuklov Similarity Theory.
The wind turbines at Altamont Pass kill more raptors than all other wind farms in the world combined. Old-fashioned wind turbines look like nice places to perch, spelling death to birds. Cracks in concrete attract rodents, which attract raptors, who get killed. The new ones are far better.
The most important thing is to keep the most important thing the most important thing. - Donald P. Coduto
© 2010 John Baez